Ore-concentrating table.



' w. s. Dunn.

Patented Ian. l5', Ism.

one couczummns TABLE.

(Application med June 32, 1900.) (No Model.)

NITED STATES PATENT OFFICE.

WILLIS G. DODD, OF SAN FRANCISCO, CALIFORNIA.

ORE-CONCENTRATING TBLE.

SPECIFICATION forming part of Letters Patent No. 666,002, dated January 15, 1901.

Application filed June 22,1900. Serial No. 21,134. (No model.)

T0 a/ZZ whom it may concern.

Beit known that I, WILLIS G. Donn, a citizen of the United States, residing in the city and county of San Francisco, State of California, have invented certain new and useful Improvements in Ore-Concentrating Tables; and I do hereby declare the following to be a full, clear, and exact description of the same.

The inven tion relates more especially to that class or type of concentrating-tables known as transversely inclined concentratingtables, and it resides more particularly in the arrangement of the rifies upon the working face of the said table. In this particular class of concentrating-tables-that is, the transversely-inclined ones-the separation of the valuable particles from the gangue takes place during the downward travel of the material over the working face of the table. The separation is due to the longitudinal action or reciprocating motion of the table and the downward iow of a body of water over the face thereof. The downward or transverse travel of the material to be or being treated is retarded by means of a series of riftles arranged longitudinally of the table, which riftles catch and confine the heavier or valuable particles separated from the gangue and divert the travel thereof from a path crosswise of the table to one longitudinal thereof. It is mainly due to the diverting of the crosswise travel of gold will be carried off with the flow of the gangue. It is the recovery of this grade of material which the present invention is designed to accomplish, while at the same time securing a better and more efficient separation of the valuable particles carried by the gangue upon the table.

The object of the present invention is to so construct the concentrating-surface of the table that the material fed thereon or delivered thereto may be deflected, so to speak, from a transverse travel or path to a longitudinal travel or path with the least possible disturbance, thus allowing of the heavier particles separated from the gangue being conveyed longitudinally of the table With the least agitation and friction and in a compact form and upon such lines as the material would traverse the surface of the table of its own accord, resulting in an increased capacity of the machine, themaking of a cleaner concentrate, and enhancing the value of the product obtained from the working of the table.

In order to comprehend the invention, reference should be had to the accompanying sheets of drawings, forming a portion of the present application, wherein- Figure lis a plan view of the improved concentrating-table. Fig. 2 is a longitudinal section view of the table in side elevation. Fig. 3 is a detail enlarged plan view of a portion of the table, illustrating the discharge ends of the riffles and the paths taken by the gangue and valuable particles as they leave' the riiiles; and Fig. 4 is a similar view illustrating the paths of the gangue and valuable particles as discharged from the ends of the ordinary straight or longitudinal riffles.

In the drawings the letter A is used to indicate a transversely-inclined concentratingtable, and A the unriflied or plain discharge end thereof. At the head-end corner of the table is arranged the feed-box B, from which the ore or pulp to be worked is delivered onto the table. It will be understood that the table is a longitudimany-reciprocating one, being driven by any suitable form of mechanism designed for this purpose, preferably that form of drive mechanism fully set forth and described in Letters Patent No.650,673, granted me on the 29th day of May, 1900,for animproved ore-concentrator.

.At the upper edge of the table, near its discharge end and above the plain 0r` unriftled Vportion A', is arranged the perforated waterdistributer B, by means of which clear water is delivered onto the plain or unriifled p0rtion of the table in order to lubricate the same and wash from the valuable material such gangue as may adhere thereto as discharged from the rifes onto this portion of the table,

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Intermediate the head end'C of vrthe table and the plain or unriffled portion A thereof is arranged a series of parallel riffles C. Each riffle is formed with an upwardly curved or head-end corner of the table, Fig. 1..

inclined portion ct near the head end of the table and a downwardly curved or inclined portion d near the plain or unrifiied portion of the table. The portion of the riffles intermediate thc upwardly and downwardlycurved or inclined ends a a are approximately straight and longitudinal with the table or its working face. These riffles gradually decrease in height from their upwardlyinclined or curved ends a toward their downwardly .inclined or curved ends ot.

surface of the table between numerals 6 and- 7 may be said to constitute the zone of the gangue.

The pulp or finely-crushed ore containing the mineral to be saved is delivered upon the table from the feed-box B, located at the course or direction of travel of the material at this point is transverse of the table. As soon as the heavier particles comein contact with the upwardly curved or inclined portion or head end of the riffles this transverse travel of the valuable particles is gradually and gently changedA into a longitudinal travel, due to the natural curve or inclination of the riffles at this point and the reciprocating motion given the table. The mineral or heavier particles are then moved longitudinally along the riffles toward the foot or unriftled portion of the table. During this travel of the mineral or valuable particles the gangue is gradually eliminated and washed over the 'riflies transverse of the table. When the mineral or valuable particles reach the end of the riflies, the velocity at which it has been moving is accelerated, due to the downward curvature or inclination of the rifes atth'is point, and it is guided into its natural `trajectory, approximating a parabolic curve, at a velocity approximately coincident with the velocity of the gangue at the outward boundary 7 of the zone of flow, causing little or no disturbance of the particles of mineral collected. The gangue `being much lighter than the mineral has an inclined trajectory. rllhe final separation of the mineral from the gangue takes place as the mineral is discharged from the riffles onto the plain or unriftled portion of the table. Now asthe trajectory of the gangue and the trajectory'of the mineral intersect each other at the point of theminerals discharge, Fig. 3 of the drawings,and the mineral crosses or passes through and out of the zone covered by the gangue Theand` enters upon the smooth or unriffled portion of thestable it continues in itscourse or natural trajectory until it passes over the tail or foot of the machine into a receptacle located at such point for its reception. While making this passage overthe unriffled portion of the table it is subjected to the action of a very slight spray of clear water delivered from the water-distributer B. This spray is for the purpose of lubricating the smooth surface of the table and for washing out any small particles ofgangue ,that may have become entangled With the mineral during its passage through the outward boundary of the gangue zone. The gangue passes downward over the riflies and acrossthe table, being discharged over its lower edge and allowed to run to waste.

The improved rifiies have two distinct features and perform two distinct functions in the operation of separating the mineral from the gangue. By reference to Fig. 1 of the drawings it will beseen that the upper or receiving end of the riffle has a gradual upward curveor'inclination, while the lower or discharge end has a reverse or downward curve or inclination. The-mineral when firstl delivered upon the table has a transverse direction, with a high velocity, which direction of the minerals travelk must be changed to alongitudinal direction with the least possible disturbance. This is accomplished by the iuclination or curvature given to the riiiies at this point. After the mineral or valuable particles have been collected within the riffles it is necessary that the mineral `be carried forward longitudinally withas little agitation as possible and in a compact form, so as to enable it to cross and pass through the outward boundary ofthe gangue Zone. The downward curvature orinclination of the discharge end of the riflies is such as to discharge the mineral on its natural trajectory in a compact form with avelocitysufticient to enable the compact bodyof mineral to cross and pass through the gangue without undue agitation or disturbance and without'being carried downward by the flow -of the gangue. The `construction of the described lriffles serves, irst, to divert the transverse travel of the mineral into a travel longitudinally of thetable, and, secondly, to enable the mineral to be discharged upon the plain or unrifled portion of the table on its natural trajectory. By thus imparting a natural discharge to the collected or separated mineral undue agitation or disturbance of `the solid mass is obviated and a more perfect concentration obtained. Again, by conlining the material between the riffles intermediate the inclined or curved ends thereof thematerial is subjected to -the concentrating actionof the table for a greater period than if the riflles were formed upon a common curvature throughout their length and the mineralthus permitted to'settle or collect in a body. As the transfer of the transverse travelof the IOO IIO

material into alongitudinal travel of the table is a gradual one at the head end of the rit'- fles, undue agitation or disturbance at this end of the riftles is overcome and to a certain extent the material is assisted in its longitudinal travel. The prevention of excessive agitation at this point prevents the iiner or lighter particles of the valuable material being carried off with the gangue.

In Fig. 4 ot' the drawings I have illustrated the disturbance and agitation which take place at the discharge end of the rifles when the table is provided with the ordinary straight riflies. In this view the arrow 8 indicates the iow of the gangue and 9 the iiow of the mineral, which meet or intersect at the point l0. It will be noticed thatin such case the mineral, so to speak, is dropped from one rifle onto the next lowest riflie and the material broken and the finer particles liberated from the solid mass. Being thus liberated, the finer particles will be carried oil? with the gangue and lost unless the waste material be treated as middlings and be returned to the tables by means of an elevator or otherwise to again undergo the process of separation.

Having thus described my invention, what I claim as new, and desire to secure protection in by Letters Patent, is-

l. A reciprocating ore-concentrating table having a plain or nnriiiied tail or foot portion, an obstructing-little arranged upon the working face of said table intermediate its head end and its plain or unriftled foot or tail portion, said rifile having an upward inclination at its head end and a downward inclination at its discharge end, the portion of the rii'tie intermediate the upwardly and downwardly inclined ends being approximately longitudinal with the working face of the table.

2. A reciprocating ore-concentrating table having a plain or unrifed tail or foot portion, an obstructing-rifle arranged upon the working face of said table intermediate its head end and its plain or unrifiled foot or tail portion, said rifile being upwardly inclined at its head end and downwardly inclined at its discharge end.

3. A reciprocating ore-concentrating table having a plain or unrifiled tail or foot portion, a series of obstructing-Hides arranged upon the working face of said table intermediate its head end and its plain or unriii'led foot portion, said riiiles having an upward inclination at their head ends and a downward inclination at their foot or discharge ends, the portion of the rifiles intermediate the upwardly and downwardly inclined ends being approximately longitudinal with the working face of the table.

ai. A reciprocating ore-concentrating table having a plain or unrifiled tail or footl portion, a series of obstructing-riftles arranged upon the workingface of the table intermediate its head end and its plain or unrifled footy portion, said riflies being upwardly inclined at their head ends and downwardly inclined at their discharge ends.

5. A reciprocating ore-cencentrating table having a series of obstructing-riftles arranged upon its working face, said rifies having an upward inclination at their head ends and a downward inclination at their discharge ends, as and for the purpose set forth.

6. A reciprocating ore-concentrating table having a plain or unrifiied foot or tail portion, an obstructing-rifiie arranged upon the working face of said table intermediate its head end and its plain or unriiiied foot or tail portion, the rifiie being upwardly inclined at its head end and downwardly inclined at its discharge end and having that portion intermediate its upwardly and downwardly inclined ends approximately longitudinal with the workin g Aface of the table, said riflle gradually decreasing in height from its head end toward its foot or discharge end.

7. A reciprocating ore-concentrating table having a plain or unrifded tail or foot portion, a series of riiiies arranged upon the working face of said table intermediate its head end and its plain or nnriiiled foot portion, said riftles being downwardly inclined at their discharge end, the portion of the riliies intermediate the head end of the table and its foot or tail end being approximately longitudinal with the working face of the table.

8. A concentrating-table having a plain or unriftled foot or tail portion and provided on its working face with an obstructing-riftle, the body portion of said rifde being approximately longitudinal with the face of the table and its head end upwardly inclined, whereby the material fed onto the table for separation has its path of travel diverted from a transverse direction into a travel longitudinal of the working face of the table.

9. A concentrating-table having a plain or unrifiied foot or tail portion and provided on its working face with an obstructing-riflie, the body portion of said riftle being approximately longitudinal with the face of the table and its discharge end downwardly inclined.

l0. A reciprocating ore-concentrating table having a plain or unriftled tail or foot portion, aseries of obstructing-rimes arranged upon the working face of the table intermediate its head end and its foot portion, said riiiles having an upward inclination at their head end and having their body portion approximately longitudinal with the working face of the table.

In testimony whereof I aix my signature, in the presence of witnesses, this 13th day of June, 1900.

WILLIS G. DODD.

In presence of- N. A. AoKER, D. B. RICHARDS.

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